This invention generally relates to home canning closures which have two components. More particularly, this invention relates to the assembly of the two components. Specifically, this invention relates to the assembly of the two components wherein a lid component is rotated through 180.degree. during the assembly process.
The two-piece home canning closure is well known in the art. The lid member of these closures has a gasket portion which co-operates with the sealing surface of the finish of a glass container to seal the container. A threaded band member is screwed onto threads on the container finish and presses against the lid to help hold it in place. Shipping of the lid and band as a unit has presented some problems. Many such units are shipped on new home canning jars which they are designed to seal. The gasket portion is relatively fragile and subject to damage which could lead to a faulty seal on the filled jar. In particular, it is undesirable to assemble the band and lid to a new jar with the gasket down, in engagement with the sealing surface of the glass container. Shipping forces and plastic flow during storage can damage the gasket in such a case. It is desirable to handle the lids with the gasket upmost prior to assembly of the band and lid, again to protect the gasket.
U.S. Pat. Nos. 3,641,959 and 3,712,453 illustrate one technique for uniting lids and bands. However, these patents teach a system which requires the lid to enter the band with the same orientation it has held in the rest of its prior handling. We have devised a method and apparatus which allows handling of the lid with the gasket upmost and then rotates the lid through 180.degree. as it is assembled with the band. This places the gasket in a position to be protected by the band during shipment and storage.